In power and free conveyor systems, it is common to have a plurality of carriers that are movable along a track by engagement with a conveyor chain. In order to accommodate obstacles or accumulation of the carriers, it is common to have a movable pusher dog on each carrier which is movable into and out of position for engagement with a lug of a conveyor chain. When the pusher dog is moved out of engagement with the lug of the conveyor chain and the movement of the carrier is thus stopped on the track, it is desirable to provide a brake to prevent retrograde movement of the carrier along the track.
It has heretofore been suggested that a cam brake member be provided on each carrier which is urged by gravity into engagement with the wheels of the carrier such as shown in U.S. Pat. No. 3,548,752. An arrangement wherein pivot parts engage the track is shown in U.S. Pat. No. 3,357,369.
Among the objects of the invention are to provide a conveyor system which utilizes an improved simple, effective, economical brake system that is operable when the pusher dog is moved in a direction to disengage it from the lug of the conveyor chain.
In accordance with the invention, an anti-back up cam member is pivoted through spring means to engage the bottom of the free track and is operated by the actuator which also moves the pusher dog out of the path of the pusher lug on the conveyor to engage the track.